Aircraft: B757
Phase of flight: Parked
Anomaly: Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural FAR; Deviation / Discrepancy - Procedural Published Material / Policy

I worked as Purser on a flight from ZZZ-ZZZ1. While walking down the jet bridge the inbound crew informed the four of us flight attendants that we have a mechanical. They discovered a missing portion of the Emergency Lighting strip on the floor by Row-12 and wrote it up. They said that it is a 'No-Go' item. When I boarded the B757-200 airplane; I immediately went to Row-12 to see the missing lighting strip. It was plain to see that the strip was missing. My three flying partners all saw it as well and noted it's nothing we have ever seen before. Soon a Maintenance employee was on board examining the area. I walked up to him and started a discussion about the missing strip. He began to explain to me how the lighting strip is NOT missing; that merely the portion of carpet in that area is what's missing. I was quite surprised by his explanation and assertively shared my complete disagreement for his assessment. How; if the pilots were to turn on the emergency lighting that the missing portion would not light up at all; and that is not normal. To further prove my point I told him I was going to ask the pilots to turn on the lighting so he could see for himself. I then walked up to the cockpit and asked the Captain if they could turn on the emergency lights so he could walk back with me and also tell the Mechanic that the missing portion does in fact exist and that it is not normal. Captain then instructed the First Officer to turn on the lighting so he could walk back with me to see the missing lighting strip. When the emergency lights were on; the lighting strip went from a lit strip to dark carpet by Row-12 then to a lit strip again. I motioned to both the Mechanic and Captain how that is not 'normal' and it's a safety issue. The Mechanic dismissed my comment as he continued with his explanation to the Captain how the plane is DESIGNED this way. I was astounded. I assertively stated that the incoming crew knew this wasn't normal; which is why they wrote it up. I and my three flying partners have never seen a missing lighting strip before and knew it wasn't normal; and now I'm to believe that Boeing designed their 757s with a missing lighting strip by Row 12?! The Captain said if the Mechanic is okay with it; then he is too. I took a picture of the missing portion by Row-12 (and happened to get the Captains feet in the picture.) The Mechanic left the plane and came back about ten minutes later. When he returned he told me that he went to a nearby gate where another B757 [aircraft] was parked and examined Row-12 on that plane and how that plane also had the same missing strip by Row-12. He showed pictures of that planes missing strip as well. I responded by telling the Mechanic that simply because another plane has a missing strip that doesn't necessarily mean it's normal and doesn't need to be addressed and/or fixed. How again the inbound crew knew to report it; how the current crew knows it's not normal and how I'm not okay with it missing due to it being a safety issue. Although I don't have Captain's authority to make a final decision about it; yet I made it known my own level of discomfort with it as it's an obvious potential safety issue. If we had to evacuate upon landing in ZZZ1; that area [of the cabin floor] would not have lit up; especially since we landed late at night. To further my correct stance on this issue; we worked on another B757 the following day out of ZZZ1. The four of us flight attendants were quick to notice a fully intact lighting strip by Row-12 on this plane. We also happened to have the same cockpit crew Captain and First Officer. I told the Captain that this plane does have the lighting strip by Row-12; how the plane is not designed to have a missing portion of the strip and that it should have been fixed on our plane yesterday. I did not receive a receptive response.I cannot help but feel that our safety was not a priority on this flight. Either the Mechanic didn't want to fix the missing strip or he somehow knew that they didn't have a replacement to fix the strip which would have caused a significant delay or potential cancellation of my flight. Regardless; no excuse should be given for allowing this plane to fly the manner in which it did. I felt as though my opinion didn't matter; didn't count and wasn't professionally regarded with the priority it should have been given. If safety is our Air Carrier's number one corporate value; they fell very short with me and my crew and all the passengers on this flight. Worked First Class [section]. A Flight Attendant working as a Purser; describes her efforts to address cabin egress safety issues after being informed that a section of the cabin floor Emergency Lighting strip was missing on their outbound B757 aircraft.